The present invention relates generally to electroactive polymer technology. More particularly, the present invention relates to an electrode used to electrically communicate with an electroactive polymer that does not contact the polymer.
Electroactive polymer transducer technology relies on a polymer that converts between mechanical and electrical energy. Compliant electrodes are attached to opposing sides of the polymer to permit electrical communication with the polymer.
Often, it is desirable to actuate different portions of a polymer without using electrodes that contact the polymer. For example, many conventional electrodes introduce surface roughnesses that are undesirable for some applications. The opaque nature of many contact electrodes may also interfere with the optical performance of a transparent electroactive polymer. Alternately, some electroactive polymer transducers employ multiple active areas, each with a customized shape, deflection, and dedicated set of contact electrodes that permit independent electrical control. Currently, the wiring resolution of each set of contact electrodes limits the number of active areas that can be used, and the size of each active area in an array. In addition, many electroactive polymers operate at high-voltages that increase switching complexity, for example, by requiring transistor cascades that are sometimes prohibitively expensive or spacious.
In view of the foregoing, an alternative form of electrically communicating with an electroactive polymer would be desirable.
The present invention overcomes the limits and deficiencies of the prior art by providing systems and methods for electrically communicating with an electroactive polymer using one or more electrodes that do not contact the polymer. A non-contact electrode communicates charge to or from a portion of the polymer, typically through a medium. For example, the medium may include air, a vacuum, or a specialized gas that facilitates transfer of charge between the electrode and the polymer. The charge may include positive or negative ions or electrodes that may be used for actuation, generation, sensing, or to diminish actuation applied to polymer in one or more specific polymer portions.
In one aspect, the present invention relates to a device for converting between electrical energy and mechanical energy. The device comprises an electroactive polymer capable of converting between electrical energy and mechanical energy. The device also comprises at least two electrodes in electrical communication with the electroactive polymer. One of the at least two electrodes is a non-contact electrode, having a portion proximate to the electroactive polymer, that transfers charge to or from a portion of the polymer through a non-condensed medium without contacting the polymer.
In another aspect, the present invention relates to a method for operating an electroactive polymer in electrical communication with at least two electrodes. One of the at least two electrodes is a non-contact electrode, having a portion proximate to the electroactive polymer without contacting the polymer. The method comprises transferring charge between the non-contact electrode and a portion of the polymer through a non-condensed medium to thereby operate the electroactive polymer.
In yet another aspect, the present invention relates to a device for converting between electrical energy and mechanical energy. The device comprises an electroactive polymer capable of converting between electrical energy and mechanical energy. The device also comprises at least two electrodes in electrical communication with the electroactive polymer. One of the at least two electrodes is a non-contact electrode, having a portion proximate to the electroactive polymer, that transfers charge to or from a portion of the polymer through air without contacting the polymer.
These and other features and advantages of the present invention will be described in the following description of the invention and associated figures.